A Pentagon investigation into how a Medal of Honor nomination was “lost” – possibly because of an improper effort to kill the award – is focused on its mishandling by members of the chain of command that included retired Army Gen. David Petraeus and other senior U.S. commanders.

A Pentagon investigation into how a Medal of Honor nomination was “lost” – possibly because of an improper effort to kill the award – is focused on its mishandling by members of the chain of command that included retired Army Gen. David Petraeus and other senior U.S. commanders.

The investigation is being conducted by the Directorate for Investigations of Senior Officials, a division of the Defense Department Office of Inspector General that handles cases involving top military and civilian defense officials.

“Specifically, officials within the Directorate for Investigations of Senior Officials are conducting an inquiry into the circumstances surrounding the lost recommendation,” the inspector general’s office wrote in a Sept. 3 letter to Rep. Duncan Hunter, R-Calif., who pressed for the probe.

The review is the latest turn in the convoluted history of the Medal of Honor nomination of former Army Capt. William Swenson, who was recommended for the nation’s highest military decoration for valor for his actions on Sept. 8, 2009, in one of the most extraordinary battles of the Afghanistan and Iraq wars. The Seattle native is scheduled to receive the medal from President Barack Obama on Oct. 15, nearly four years after he was first nominated and more than a year after his papers reached the White House.

The inspector general’s “investigation is looking at the approval process for Capt. Swenson’s award, specifically how the chain of command mishandled his nomination,” said Joe Kasper, a spokesman for Hunter.

Bridget Serchak, a spokeswoman for the inspector general’s office, declined to comment on the matter, saying she could not discuss any ongoing case.

The consequences of the investigation are unclear. Typically, the inspector general’s office refers cases in which allegations of regulation violations are substantiated to the secretary of defense or the service secretaries for further action. Cases in which evidence of crimes is found are sent to the Defense Criminal Investigative Service for further investigation, often in conjunction with the Department of Justice.

Swenson, 34, will be the first living U.S. Army officer to receive the medal in more than 40 years. He was recommended for his role in extracting a small group of American military advisers trapped in an eastern Afghanistan valley by a Taliban ambush and then leading U.S. and Afghan forces on repeated forays back into the valley to recover casualties while under vicious enemy fire.

Four U.S. servicemen, nine Afghan security forces and a translator died in the six-hour clash outside the village of Ganjgal. A fifth U.S. soldier, who was among some two dozen American and Afghan wounded, died two months later.

A slew of decorations were awarded to survivors of the battle, including a Medal of Honor for Marine Sgt. Dakota Meyer, and two Navy Crosses. Moreover, two Army officers were reprimanded for dereliction of duty for failing to provide air and artillery support for the Afghan troops and their American military advisers.

A chain of U.S. officers and senior officials – beginning in the field and ending with former Defense Secretary Leon Panetta – were required to recommend approval or disapproval for Swenson’s nomination.

Petraeus, based in Kabul, commanded the U.S.-led international force in Afghanistan in the summer of 2010, when Swenson’s original Medal of Honor packet – the telephone book-size package of sworn witness statements, maps and other documents supporting the nomination – went missing. Every electronic copy of the packet also disappeared from U.S. military computer systems, except for an incomplete version that was found on a classified network.

A duplicate file was assembled in July 2011 and sent up the chain of command. At the time, U.S. military spokesmen asserted that an internal investigation found that Swenson’s original packet was “lost” through bureaucratic bungling because of a high staff turnover rate at USFOR-A, the headquarters of the U.S. military contingent serving in Afghanistan.

But according to an Aug. 4, 2011, Memorandum of Record obtained by McClatchy, the “informal” investigation failed to pinpoint the reason why Swenson’s paperwork disappeared. Moreover, the probe was closed despite uncovering evidence of a possible attempt to kill Swenson’s award through an improper downgrade to a Distinguished Service Cross.

Under Defense Department and Army regulations, only the president of the United States has the authority to downgrade a Medal of Honor nomination to a lower award.

The memorandum – a report on the results of the internal investigation – said the probe “did not reveal any suspected criminal activity.”

It mirrored a U.S. military letter outlining those findings that McClatchy reported in August 2012. The memorandum, however, contains details that were not in the first document.

Petraeus, while serving as the CIA director, told McClatchy last year that he had “no recollection of seeing” Swenson’s packet. The memorandum noted that Petraeus signed Swenson’s packet on July 28, 2010. Petraeus didn’t respond to several email requests for a telephone call to discuss the discrepancy.

Another new detail: Briefing slides tracking the status of military award nominations in eastern Afghanistan showed that Swenson’s packet was one of two Medal of Honor nominations sent to USFOR-A on the same day, May 19, 2010.

The second nomination was from a separate battle, and the identity of the nominee was redacted. But both packets were processed concurrently, according to the memorandum. Yet while the second proceeded through the system, Swenson’s Medal of Honor packet disappeared.

The second packet “was logged and tracked through the same process,” said the memorandum. “It is reasonable to assume that had both . . . MoH packets been submitted at the same time, as indicated by the slides, both would have been tracked and processed in the same manner.”

A footnote on an Aug. 21, 2010, briefing slide uncovered by the internal investigation provided a clue to what happened to Swenson’s Medal of Honor packet.

Swenson’s “award was downgraded to DSC (Distinguished Service Cross). USFOR-A is currently out of certificates, but will process . . . ASAP,” the footnote said. The memorandum commented that the footnote “appears to be an error as USFOR-A does not have the authority to downgrade a MoH (Medal of Honor).”

But a second briefing slide, dated Aug. 28, 2010, also said that Swenson’s “award was downgraded to DSC” before being “forwarded to CENTCOM.” CENTCOM is the Tampa, Fla.-based U.S. Central Command, which oversees all U.S. military forces from Pakistan through the Middle East.

In an Aug. 9 letter to Acting Department of Defense Inspector General Lynne Halbrooks, Hunter noted that an executive summary of the internal investigation’s findings signed by then-Army Maj. Gen Timothy McHale, who oversaw the USFOR-A staff, made no mention of the award downgrade noted in the slides.

In his letter, Hunter pointed to other “inconsistencies . . . that warrant further examination,” including how Swenson’s original paperwork could have disappeared when the second nomination did not.

Hunter also asked how Swenson’s original file could have vanished from an Army computer system dedicated to awards, and why the Medal of Honor packet for Meyer, the other nominee from the Ganjgal battle, was not processed through the U.S. headquarters in Kabul.

Hunter, a former Marine officer who served two combat tours in Iraq and one in Afghanistan, has been leading demands for an overhaul of the military’s award system. He charges that the system is vulnerable to improper influence and manipulation, resulting in the awarding of too few Medals of Honor and other awards for bravery during the past 12 years of war. The Pentagon denies the allegations.

In an interview, Hunter said that he pressed for the inspector general’s investigation into what happened to Swenson’s original nomination because the case is emblematic of the larger problems with the award system.

“It’s a broken process. It’s a politicized, bureaucratic process,” he said. “We want to point out the problems with it so it doesn’t happen again. And we want people held accountable.”